For construction machinery equipped with an engine, there is a technical problem to solve, which is to reduce particulate matter (which may hereinafter be simply referred to as PM) such as soot contained in exhaust gas discharged from the engine. In order solve the problem, the construction machinery includes, for example, filters in an exhaust gas pipe, a muffler, and the like. PM is collected by the filters, and then the exhaust gas is discharged to the atmosphere.
However, if PM is kept collected, then the PM builds up inside the filters, thereby clogging the filters. In order to suppress such clogging, it is necessary to remove the PM that has built up from the inside of the filters. One of the methods for removing PM is, for example, increasing the load torque of the engine to increase the temperature of the exhaust gas, thereby burning the PM to remove the PM. For example, Patent Literature 1 discloses a work machine that realizes such a PM removal method. The work machine disclosed in Patent Literature 1 is configured such that a controller controls the discharge flow rate of a pump, the discharge pressure of the pump, and an engine speed, thereby increasing the load torque of the engine to increase the temperature of the exhaust gas.